System for Wireless Charging of a Plurality of Devices

ABSTRACT

A master unit for wirelessly charging a slave device includes a plurality of radio frequency integrated circuit (RFIC) modules, each of the plurality of RFIC modules having an antenna array. The master unit is configured to select one of a single beam mode by using all or substantially all antenna arrays in the plurality of RFIC modules, a multi-beam mode by using each respective antenna array in each of the RFIC modules to form a separate beam from each RFIC module, and a customized beam pattern mode by using a customized combination of antennas in selected ones of the plurality of RFIC modules. The master unit is configured to dynamically select from one of the single beam mode, the multi-beam mode, and the customized beam pattern mode based on a location of the slave device relative to the master unit.

RELATED APPLICATION(S)

The present application claims the benefit of and priority to aprovisional patent application titled “Wireless RF Charging usingBeamforming and Distributed Transceivers,” Ser. No 62/204,605, filed onAug. 13, 2015. The disclosure in this provisional application is herebyincorporated fully by reference into the present application.

BACKGROUND

Wireless charging is convenient because it removes the need for wiresand connectors. For instance, wireless charging using RF powertransmission does not require a device being charged to be placed at afixed location or be tethered to a fixed power outlet by wire.

In a wireless charging system, a master unit can be used to transmitpower to a slave device. To optimize power delivery, the location of theslave device receiving power relative to the master unit transmittingpower needs to be taken into consideration.

For example, the electromagnetic fields surrounding one or more antennasof the master unit can be divided into a near-field region and afar-field region. In the far-field region, the radiation pattern of theantennas stays relatively constant with respect to distance. When theslave device is located in the far-field region of the antennas, theantennas can focus a beam toward the slave device. However, as the slavedevice moves closer to the master unit, it enters the near-field region.Without proper adjustment to the antenna configuration, the far-fieldradiation pattern formed by the far-field antenna configuration may notachieve optimal power delivery when the slave device moves into thenear-field region. For example, some of the antennas used to formfar-field radiation patterns may not be useful to form near-fieldradiation patterns, thus wasting energy and computing resources of themaster unit.

Thus, there is need in the art to provide a master unit that candynamically configure its antennas to adjust its radiation pattern basedon the location of a slave device to optimize power delivery in awireless charging system.

SUMMARY

The present disclosure is directed to a wireless charging system,substantially as shown in and/or described in connection with at leastone of the figures, and as set forth in the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an exemplary system for wireless charging accordingto one implementation of the present application.

FIG. 2A illustrates an exemplary master unit according to oneimplementation of the present application.

FIG. 2B illustrates a portion of an exemplary master unit according toone implementation of the present application.

FIG. 3 illustrates an exemplary slave device according to oneimplementation of the present application.

FIG. 4A illustrates an exemplary master unit in a single beam modeaccording to one implementation of the present application.

FIG. 4B illustrates an exemplary master unit in a multi-beam modeaccording to one implementation of the present application.

FIG. 4C illustrates an exemplary master unit in a customized beampattern mode according to one implementation of the present application.

FIG. 5A illustrates an exemplary system for wireless charging accordingto one implementation of the present application.

FIG. 5B illustrates exemplary system for wireless charging according toone implementation of the present application.

FIG. 6 illustrates an exemplary slave device having a configurablenetwork of capacitors according to one implementation of the presentapplication.

FIG. 7 illustrates a coexistence of multiplexed power and data deliveryin time domain according to one implementation of the presentapplication.

FIG. 8 illustrates a coexistence of multiplexed power and data deliveryin frequency domain according to one implementation of the presentapplication.

DETAILED DESCRIPTION

The following description contains specific information pertaining toimplementations in the present disclosure. The drawings in the presentapplication and their accompanying detailed description are directed tomerely exemplary implementations. Unless noted otherwise, like orcorresponding elements among the figures may be indicated by like orcorresponding reference numerals. Moreover, the drawings andillustrations in the present application are generally not to scale, andare not intended to correspond to actual relative dimensions.

Referring to FIG. 1, FIG. 1 illustrates an exemplary system for wirelesscharging according to one implementation of the present application. Asillustrated in FIG. 1, system 100 includes network/cloud 102, server104, database 106 having slave device information database 106 a, masterunit information database 106 b, and pairings/associations database 106c, master units 108 a and 108 b, and slave devices 110 a, 110 b, 110 cand 110 d. Although only two master units and four slave devices areshown, it should be understood that system 100 may have many differentconfigurations with different numbers of master units and slave devices.

As illustrated in FIG. 1, master units 108 a and 108 b are eachconnected wirelessly to network/cloud 102 through a wireless link ineither a packet-based/non-packet based network or a wired/wirelessnetwork, e.g., Bluetooth, Wireless Local Area Network (WLAN),third/fourth/fifth generation (3G/4G/5G) or LTE (Long Term Evolution)cellular, Code Division Multiple Access (CDMA), Time Division MultipleAccess (TDMA), Worldwide Interoperability for Microwave Access (WiMAX),Ultra-Wide Wide Band (UWB), 60 GHz, and etc. In one implementation, amaster unit can transmit multiple beams to charge multiple slavedevices, where each beam is steered and focused on a different slavedevice. For example, master unit 108 a steers and focuses beams 139 aand 139 b to charge slave device 110 a (e.g., a wearable device) andslave device 110 b (e.g., a sensor), respectively. In anotherimplementation, a master unit can transmit a single beam and charge asingle slave device, where the single beam is steered and focused on thesingle slave device. For example, master unit 108 b steers beam 139 d tocharge slave device 110 d (e.g., a smartphone). In yet anotherimplementation, two or more master units can coordinate with each other,or are coordinated by a slave device and/or through a network by aserver or a remote user/administrator who uses a networked computingdevice, to steer their beams onto the slave device for charging thatdevice.

In an implementation, the slave devices may differ in their power statusand capability. For example, slave device 110 a (e.g., a wearabledevice) may have a low battery charge, while slave devices 110 b (e.g.,a sensor) and 110 d (e.g., a smartphone) may have no battery charge.Slave device 110 c (e.g., an Internet of Things (IoT)) may have beenfully charged. The charging of each of slave devices 110 a, 110 b, 110 cand 110 d can be done wirelessly through radio frequency transmission.

In some implantations, system 100 uses master units 108 a and 108 b withnarrow directional focused beams to provide wireless power to slavedevices 110 a, 110 b, 110 c and 110 d. The focusing of the beam providesmore power and energy for charging the slave devices. Each of the masterunits is typically a bigger system with a good power source (e.g. AC ora good battery life), whereas the slave devices have limited sources ofpower (e.g. limited battery or no battery). The master units can bestand-alone chargers, or they can be integrated into bigger systems suchas a car, PC, laptop, tablet, cell phone, digital/video camera, or amultimedia device such as an iPod®. The slave devices could be anynon-battery device (e.g. memory stick or memory device) or batteryoperated device. Some examples of slave devices are laptop, tablet, cellphone, PDA, wireless headset, wireless mouse, wireless keyboard, pager,digital/video camera, external hard drive, toy, electronic book reader,sensor, CD/DVD/cassette/MP3 player, toothbrush, lighting devices,electronic appliances, wearable devices such as a digital watch, orInternet of Things (IoT) devices, or even a car. The IoT device categorymay include remote sensors, smart meter devices, security alarms, safetymonitoring devices, health monitoring sensors, among others. AC poweredslave devices could also use this system as a backup power in case ACpower goes off. Thus, a master unit could power up an AC powered slavedevice that temporarily has lost its AC power source. In someimplementations, the master unit could be just a dedicated chargingdevice and not communicate with the slave device other than forcharging. In other implementations, master units are networked andcommunicates with the slave devices not only for control data forcharging, but also for other data communication.

In some implementations, only authorized slave devices may receive powerfrom one or more master units. In an implementation, charging isinitiated by a slave device or by a master unit when the two are closeto each other, for example either automatically or by pressing a buttonon the slave device or the master unit. In an implementation, a masterunit selects which slave devices to power up and communicate with.

The slave devices have identifying information about themselves storedin their memories or in a database accessible by a network. The storedinformation can include one or more of the slave devices' media accesscontrol address (MAC address or MAC ID), network IP address, name,serial number, product name and manufacturer, capabilities, and etc. Themaster unit (or a controller device such as a network server, or aremote user) requests that information. In another implementation, theslave devices are proactive and communicate with the master unit (or acontroller device such as a network server, or a remote user) if theyhave power (e.g., “charge my battery,” or “I want to send you somedata,” etc.) and provide their identifying information and registerthemselves in a slave device information database. In yet anotherimplementation, the master unit has access to a slave device informationdatabase that includes an authorized list. This database is locallystored on the master unit or it is stored on a possibly larger networkeddatabase (e.g., slave device information database 106 a in database 106).

In some implementations, a master unit that employs a focuseddirectional RF beam uses beam steering to focus the beam on a particularslave device, power the slave device up slightly to get slave device'sidentifying information, and only continue powering up/charging andcommunication if the slave device's identifying information match withan entry on the authorized list. For instance, only a slave device witha certain MAC ID, network IP address, name, serial number, product name,manufacturer, capabilities, etc. may be powered up, charged orcommunicated with. For RF-based systems, frequency hopping methods arealso used in some implementations by the master unit and authorizedslave devices to allow them to get power while unauthorized nearby slavedevices (that do not know the hopping sequence) do not receive muchpower. Similarly, a master unit that employs focused RF beams uses timehopping and/or frequency hopping to power up multiple slave devices. Insome implementations, an authorized user/administrator can override thesystem and allow charging of an unauthorized slave or add the slave tothe authorized list. The database for authorized slave devices can belocally stored on the master units or it may be stored on a networkeddatabase on the network cloud. In the latter case, the master unitscould access the networked database and check the slave's authorizationprior to charging. In some implementations, the user of a slave devicecan make a payment to a server/store owner in order to have the slavebecome authorized for charging by specific master units.

In some implementations, only authorized master units may transfer powertransfer to one or more slave devices. In an implementation, a slavedevice prevents non-authorized master units from trying to charge it orpower it up (or networked servers from commanding master units to chargeit or power it up). Slave devices can store identifying informationabout master units (or networked servers) that are authorized to chargethem. The stored information about authorized master units or networkservers can include one or more of the following information about themaster units: the master units' media access control address (MAC ID),network IP address, name, serial number, product name and manufacturer,capabilities, etc. The slave device requests identifying informationfrom the master unit or the network server. In another implementation,the master unit (or the network server) is proactive and sends itsidentifying information to the slave device. In another implementation,the master units register themselves and their identifying informationin a master unit information database (e.g., master unit informationdatabase 106 b in database 106). The slave device checks the masterunit's information with the authorized list and if there is not a match,the slave device disables charging and/or power-up. In someimplementations, the user of a slave device can override the system andallow access to an unauthorized master unit or add the master unit tothe authorized list. The database for authorized master units can belocally stored on the slave devices or it may be stored on a possiblylarger networked database on the network cloud. In the latter case, theslave device could access the networked database and check the masterunit's authorization prior to allowing that master unit to charge it.

In some implementations, pairings/associations database 106 c indatabase 106 is utilized to store and maintain information about slavedevices and master units that are known to have been previouslypaired/associated by the network. Further, new slave devices and masterunits can be authorized to be added to pairings/associations database106 c by a slave device, a master unit, and/or a network authorizedadministrator.

In some implementations, the selection and power scheduling of slavedevices are dependent on the priorities of slave devices' functions ordata. For example, slave device 110 a with a higher priority gets fiveminutes of scheduled charging time, while slave device 110 b with alower priority gets three minutes of scheduled charging time. In animplementation, a slave device information database stored at the masterunit or a slave device information database stored in a databaseaccessible by the network may include priorities for slave devices andtheir data. In an implementation, the slave devices also communicatetheir data (and possibly the priority of their data) to the master unit.Based on this information the master unit then decides on a course ofaction. In some implementations, the user of a slave device can pay moreto a subscription service or store owner to have higher chargingpriority as compared to other slave devices that have paid less.

In different implementations, the power status of the slave devices andtheir power-related requests and the master unit's response strategy mayvary significantly. The followings are several examples: (1) Slavedevice has battery and power and is ready to communicate. Master unitmay communicate; (2) Slave device has battery and some charge, and slavedevice requests to communicate. Master unit may allow communication oroverrule and charge the slave device further first (e.g. if aftercommunicating the quality of slave device data is not high because ofthe low power status of slave device); (3) Slave device has battery andsome charge, but slave device requests to be fully charged. Master unitmay honor the request and charge the slave device or may overrule andcommunicate with the slave device (e.g. if live communication has higherpriority); (4) Slave device has battery but battery has no charge.Master unit may charge the battery first or just power up the slavedevice and communicate first if communication priority is high; (5) Foroptions 1, 2, 3, and 4 above if after communicating a slave device'sbattery charge level reaches zero or some pre-determined low level thenthe battery is charged to some higher pre-determined level beforeresuming communication; (6) For options 1, 2, 3, and 4 above if there issufficient power transferred from the master unit to the slave devicethen the slave device may communicate at the same time that the masterunit is charging the battery; (7) Slave device has battery and after itis charged by the master unit to a sufficient level the slave deviceconnects and communicates with nodes in another network (e.g. slavedevices 110 a, 110 b, 110 c and 110 d connect to Bluetooth, WLAN,3G/4G/5G or LTE cellular, WiMax, UWB, 60 GHz and mesh ad-hoc networks).The master unit optionally continues to charge the slave device orcharge the slave device once the slave device's battery levels reachpre-set low levels; (8) slave device has no battery and needs to bepowered up before communication. Master unit powers up the slave devicebefore communicating.

In some implementations, the same frequency band/channel is used forboth charging the slave device and communication, while in otherimplementations, different channels are used for charging andcommunication (e.g. two RF channels with different frequencies—one forcharging and one for communication). In some implementations, the masterunit also uses a control channel to inform the slave devices what itwants to do. Thus, all the commands could come over the control channel,although it is also feasible to send commands over the datacommunication channel as well. The control channel does not need to havehigh bandwidth. Thus, while the communication channel and the controlchannel use the same frequency in some implementations, the controlchannel uses a lower frequency, lower bandwidth, and lower power channelthan the communication channel. The master unit may also use aninduction charger or RF charger to charge its own battery if its powersource is a rechargeable battery instead of AC power.

In an implementation, when the master unit is connected to a network(e.g., packet-based or non packet-based, Bluetooth, WLAN, 3G/4G/5G orLTE cellular, TDMA, CDMA, WiMax, UWB, 60 GHz, etc., or wired connection)then a powered up or charged slave device is also connected to the samenetwork through the master unit. In another implementation, when a slavedevice is connected to a network (Bluetooth, WLAN, 3G/4G/5G or LTEcellular, WiMax, UWB, 60 GHz, etc., or wired connection) then the masterunit gets connected to that network after the master unit charges thatslave device. Thus, after powering up, that slave device not only is aslave device able to connect to its wireless network (Bluetooth, WLAN,3G/4G/5G or LTE cellular, WiMax, UWB, 60 GHz, etc.) but the master unitis also able to connect to those networks through that slave deviceacting as a network node. In some implementations, if a master unit doesnot have a network connection and a slave device does, the master unitcharges the slave device and use its network connection to connect tothe network and perform networked operations such as downloadingsoftware and driver upgrades.

In some implementations, a slave device that gets powered up acts as anetwork node and communicates with other slave devices to form a meshnetwork. For instance, in FIG. 1, slave device 110 a is initiallypowered up by master unit 108 a. Master unit 108 a cannot communicatewith slave device 110 b because slave device 110 b is not within itscommunication range. However, master unit 108 a can communicate withslave device 110 a, and slave device 110 a can in turn communicate withslave device 110 b. Likewise, slave device 110 b can communicate withslave device 110 c, etc. Thus, by charging slave device 110 a, masterunit 108 a has connected itself to a mesh network of slave devices andother networks that it was not connected to before.

In some implementations, slave devices that get charged may act asmaster units to charge other slave devices. In FIG. 1, slave device 110d is charged by master unit 108 b. Slave device 110 b also needs to becharged. In one implementation, slave device 110 d may act as a masterunit to charge slave device 110 b. This may for example be because slavedevice 110 b is too far from master unit 108 b for charging.

In some implementations, a network server is in command and is the“real” master unit. For example, in FIG. 1, server 104 instructs masterunit 108 b to power up the slave devices in its vicinity and requestsinformation from the slave devices. Master unit 108 b then sends theslave devices' identifying information and any matching entries it hasin its own database (together with any slave device requests) to server104, server 104 further searches slave device information database 106 afor additional identifying and matching information, and then instructsmaster unit 108 b on a course of action (e.g. charge one or moreauthorized slave devices, but no further action with unauthorized slavedevices). In some implementations, an authorized remote user can usenetwork/cloud 102 to connect to and control server 104, which in turncontrols master units 108 a and 108 b as just described. Thus, dependingon which component is in control (remote user, server, or a master unit)that component monitors the power status of the slave devices, decideswhich subset of those slave devices get charged and what their chargingpriorities are.

In some implementations, the master unit uses a narrow focused RF beamfor charging. Converting RF signals to DC power can be done inRadio-Frequency Identification (RFID) far-field applications. Innear-field RFID applications, where the distance between the RFID readerand the tag is less than the wavelength of the signal, mutual inductancecan be used for communication. However, in far-field RFID applications,where the separation distance between the RFID reader and the tag ismuch greater than the wavelength of the signal, backscattering can beused for communication. With backscattering a tag first modulates thereceived signal and then reflects it back to the reader.

There are several important differences between the disclosedimplementations of the present application and those of far-field RFIDwhich are described in the present application. For instance, RFID doesnot use directional beams and hence spreads the power of thetransmission over a wider space and unnecessarily exposes humans toelectromagnetic radiation. RFID tags also require little power tooperate (e.g. the receive power is of the order of 200 microwatts)compared to the slave device devices that the disclosed implementationsof the present application powers-up and communicates with. For example,the receive power for the slave devices in some implementations of thepresent application is of the order of milliwatts and higher. The upperreceive power range depends on the transmit drivers and the size of thecoils or antennas, and in some implementations goes above the Wattrange. RFID operates in lower frequencies (e.g. less than 960 MHz) andhence provides smaller communication bandwidths and requires much biggerantennas compared to the higher frequencies used in differentimplementations of the present application. Also, RFID usesbackscattering for communication which is a low data rate method becausethe antenna is turned on and off by the data like an on-off modulationswitch. The implementations of the present application provide a muchhigher data rate because standard wireless transceiver modulationmethods are used (e.g. modulations for cellular, IEEE 802.11 standards,Bluetooth) and then the data is sent to the antenna.

In contrast to RFID, some implementations of the present application usenarrow directional focused beams in order to simulate a wire connectionfor charging and communication. This focusing of the beam provides morepower and energy for charging slave device devices. A directionalantenna is an antenna which radiates the power in a narrow beam along acertain angle and directed to a certain area or receive antenna. Someimplementations of the present application use directional antennas thatprovide a large gain in their favored direction. Some implementationsuse a group of antennas (an antenna array) arranged to provide a largegain in a favored direction.

Referring to FIG. 2A, FIG. 2A illustrates an exemplary master unitaccording to one implementation of the present application. As shown inFIG. 2A, master unit 208 includes radio frequency integrated circuit(RFIC) modules 212 a, 212 b, 212 c and 212 d, power source 214, digitalsignal processor (DSP) for charging algorithms 216, WLAN/BT sub-systemfor control 218, network card 220, memory 224, and processor forprogramming, applications, and high-level algorithms 226. As illustratedin FIG. 2A, master unit 208 may have its own power source or beconnected to a power outlet, and deploy one or more RFIC modules 212 a,212 b, 212 c and 212 d for transmitting power to one or more slavedevices. Also, master unit 208 may be connected to a network, such asnetwork/cloud 102 in FIG. 1, through its network card 220 using either awired or wireless connection. Power source 214 such as a radio frequencypower source is coupled to DSP for charging algorithms 216, whichtogether provide power and phase shift signals to one or more RFICmodules 212 a, 212 b, 212 c and 212 d to focus the transmit power on oneor more slave devices for optimum power transfer. DSP for chargingalgorithms 216 possesses signal processing capabilities for processingdata and implementing algorithms related to programming and configuringRFIC modules 212 a, 212 b, 212 c and 212 d within master unit 208 by,for example, providing them with phase shift signals. WLAN/BT sub-systemfor control 218 is configured to exchange information with one or moreslave devices through a low power communication link, such as a lowenergy Bluetooth/WLAN channel. For example, feedback provided by one ormore slave devices through this control channel may be used foradjusting the configurations of the master unit.

Referring to FIG. 2B, FIG. 2B illustrates a portion of an exemplarymaster unit according to one implementation of the present application.As illustrated in FIG. 2B, RFIC module 212 may correspond to any of RFICmodules 212 a, 212 b, 212 c and 212 d of master unit 208 in FIG. 2A. Inthe present implementation, RFIC module 212 includes phase shifters 232a and 232 b and amplifiers 234 a and 234 b coupled to antenna 236 a.RFIC module 212 also includes phase shifters 232 x and 232 y andamplifiers 234 x and 234 y coupled to antenna 236 y. Phase shifters 232a and 232 b through phase shifters 232 x and 232 y can be individuallyprogrammed, by DSP for charging algorithms 216 in FIG. 2A, to form andconfigure radiation patterns for optimal power transfer to one or moreslave devices based on their locations relative to one or more RFICmodules 212 a, 212 b, 212 c and 212 d of master unit 208, for example.In an implementation, amplifiers 234 a and 234 b through amplifiers 234x and 234 y may be power amplifiers or variable gain amplifiers.Although only two antennas and four phase shifter-amplifier branches areshown in FIG. 2B, it should be understood that RFIC module 212 may havemany different configurations with different numbers of antennas, phaseshifters and amplifiers.

In the present implementation, dual power amplifiers and phase shiftersper antenna are deployed. For example, phase shifter 232 a and amplifier234 a are configured to phase shift and amplify, respectively, a signalhaving horizontal (H) polarization, while phase shifter 232 b andamplifier 234 b are configured to phase shift and amplify, respectively,a signal having vertical (V) polarization. Antenna 236 a has dual feedsfor horizontal and vertical polarizations. Similarly, phase shifter 232x and amplifier 234 x are configured to phase shift and amplify,respectively, a signal having horizontal (H) polarization, while phaseshifter 232 y and amplifier 234 y are configured to phase shift andamplify, respectively, a signal having vertical (V) polarization.Antenna 236 y has dual feeds for horizontal and vertical polarizations.

For each antenna, a signal provided at each polarization feed,H-polarization feed and V-polarization feed, passes through a separatephase shifter and amplifier path. Therefore, the relative power betweenthe two polarizations can be adjusted through the separate amplifiers.Also, the relative phases between the two feeds can be controlledthrough the two separate phase shifters. The availability of twopolarization feeds with programmable relative power and phase enablesthe master unit to create a polarization setting that is aligned withthe polarizations at antennas of the slave device when it is charging.Even in implementations where the slave device supports a singlepolarization antenna implementation, the power delivered to thereceiving antennas of the slave device is aligned with its polarizationfor maximum power harvest, for any propagation realization and relativeorientation between the master unit and the slave device.

Tracking and search algorithms may be used to identify the relativepower and phase of signals feeding to the antennas of the master unit.In some implementations, an iterative search may be conducted where themaster unit would sweep over several combinations, and the slave devicewould report back the harvested power level per each combination throughthe low power control link. The best combination would then be selectedfor power delivery. A new search may be triggered periodically orperformed as the environment changes.

In some implementations, different RFIC modules within the master unitmay operate at different RF carrier frequencies. These RF frequenciesmay belong to the same band (e.g., operating at different frequencieswithin the 60 GHz band), or they may belong to different RF bands (e.g.,operating at a combination of 60 GHz, 5 GHz, 2.4 Ghz, and 900 MHzbands). In some implementations, different antennas each optimized for afrequency band are deployed. For examples, different physical antennasare deployed (one tuned to 2.4 GHz, another to 5 GHz, etc). In otherimplementations, a configurable single antenna structure is deployedthat can be configured to resonate and radiate at different frequencybands (e.g. 2.4 GHz band, 5 GHz band, 60 GHz band) depending on thefrequency of operation.

Referring to FIG. 3, FIG. 3 illustrates an exemplary slave deviceaccording to one implementation of the present application. Asillustrated in FIG. 3, slave device 310 includes antennas 340 a through340 y, dual matching circuits 342 a and 342 b for antenna 340 a, throughdual matching circuits 342 x and 342 y for antenna 340 y, dual phaseshifters 344 a and 344 b for antenna 340 a, through dual phase shifters344 x and 344 y for antenna 340 y, voltage multipliers 346 a through 346y, rectifiers 348 a through 348 y, power combiner 350, battery/capacitor352. Slave device 310 may also include other components, such as WLAN/BTsub-system for control 354, memory 356, digital signal processor (DSP)for charging algorithms 358, and processor for programming,applications, and high-level algorithms 360.

In one implementation, phase shifters 344 a and 344 b through phaseshifters 344 x and 344 y may be optional for power combining acrossdifferent polarizations and antennas before delivering the combinedpower to the corresponding rectifiers, such as rectifiers 348 a through348 y, respectively. Voltage multipliers 346 a through 346 y may be usedto adjust the voltage levels of the signals that feed to rectifiers 348a through 348 y, respectively, for example to match the required levelspecified in the rectifiers' specifications. The harvested power fromrectifiers 348 a through 348 y can then be combined by power combiner350 and used to charge battery/capacitor 352. Although antennas 340 athrough 340 y are shown in FIG. 3 to have dual feeds for horizontal andvertical polarizations, in another implementation, antennas 340 athrough 340 y may each have a single polarization feed.

Referring to FIG. 4A, FIG. 4A illustrates an exemplary master unit in asingle beam mode according to one implementation of the presentapplication. In the present implementation, master unit 408 in FIG. 4Amay correspond to at least one of master units 108 a and 108 b in FIG.1, and master unit 208 in FIG. 2A. As illustrated in FIG. 4A, masterunit 408 includes RFIC modules 412 a, 412 b, 412 c and 412 d, each ofwhich includes an antenna array of antennas 436.

As illustrated in FIG. 4A, in the single beam mode, master unit 408 usesall or substantially all antenna arrays in RFIC modules 412 a, 412 b,412 c and 412 d to form single beam 439, for example, toward a slavedevice (not explicitly shown in FIG. 4A). In the present implementation,as master unit 408 selects the single beam mode, all or substantiallyall antennas 436 in each of RFIC modules 412 a, 412 b, 412 c and 412 dare coordinated and co-phased to form a single powerful beam at a singleRF frequency F_(RF1). Master unit 408 selects the single beam mode whenthe slave device is at the far-field range of antennas 436 of masterunit 408. As the slave moves closer to master unit 408, master unit 408may dynamically switch from the single beam mode to a multi-beam mode ora customized beam pattern mode based on the location of the slave driverelative to master unit 408.

Referring to FIG. 4B, FIG. 4B illustrates an exemplary master unit in amulti-beam mode according to one implementation of the presentapplication. In the present implementation, master unit 408 in FIG. 4Bcorresponds to at least one of master units 108 a and 108 b in FIG. 1,and master unit 208 in FIG. 2A. As illustrated in FIG. 4B, master unit408 includes RFIC modules 412 a, 412 b, 412 c and 412 d, each of whichincludes an antenna array of antennas 436. In the multi-beam mode,master unit 408 reconfigures its RFIC modules 412 a, 412 b, 412 c and412 d and their corresponding antennas 436 to function as foursub-arrays each forming a separate beam. For example, the correspondingantennas 436 in each of RFIC modules 412 a, 412 b, 412 c and 412 d formfour separate beams 439 a, 439 b, 439 c and 439 d, respectively. In oneimplementation, the antenna array of each of RFIC modules 412 a, 412 b,412 c and 412 d is configured to operate at a different frequency, suchas F_(RF1), F_(RF2), F_(RF3), and F_(RF4), respectively.

In contrast to the single beam mode, where all or substantially all ofantennas 436 in each of RFIC modules 412 a, 412 b, 412 c and 412 d arecoordinated and co-phased to form a single beam, in the multi-beam mode,master unit 408 utilizes each respective antenna array in each of RFICmodules 412 a, 412 b, 412 c and 412 d to form a separate beam in eachRFIC module. By splitting the single large array into smallersub-arrays, the far-field range in the multi-beam mode becomes closer tothe smaller sub-arrays, because the far-field range is scaled downproportional to the number of antennas of the antenna array. As aresult, the separate antenna arrays of RFIC modules 412 a, 412 b, 412 cand 412 d lead to a smaller range for delivering power, and are suitablefor delivering power to one or more slave devices in the near-fieldrange.

In some implementations, the multi-beam mode shown in FIG. 4B may beutilized when master unit 408 cannot reliably determine an antennaconfiguration that points a high fidelity narrow and directional beam atthe slave device. As illustrated in FIG. 4B, each of beams 439 a, 439 b,439 c and 439 d has a greater beam width than that of beam 439 in FIG.4A. As a result, beams 439 a, 439 b, 439 c and 439 d may provide betterdiversity and fidelity in successfully delivering power to one or moreslave devices. Furthermore, the multi-beam mode may be utilized whenregulatory limitations on power emission levels (e.g., maximumEquivalent Isotropically Radiated Power—EIRP) does not allow for forminga highly directional beam that utilizes all antenna elements for asingle beam and a single frequency. In some implementations, beams 439a, 439 b, 439 c and 439 d formed by respective antenna arrays in RFICmodules 412 a, 412 b, 412 c and 412 d may have the same frequency orfrequency band. For example, F_(RF1), F_(RF2), F_(RF3), and F_(RF4) mayhave the same frequency or frequency band. In some implementations,master unit 408 is configured to charge multiple slave devices usingbeams 439 a, 439 b, 439 c and 439 d in the multi-beam mode. For example,master unit 408 is configured to charge four separate slave devicesusing corresponding beams 439 a, 439 b, 439 c and 439 d in themulti-beam mode.

In some implementations, power delivery robustness is a figure of merit,in which case transmitting power over four beams and differentfrequencies can lead to higher robustness and reliability. In otherwords, since the antenna array of each of RFIC modules 412 a, 412 b, 412c and 412 d is configured to operate at a different frequency, such asF_(RF1), F_(RF2), F_(RF3), and F_(RF4), the interference betweenneighboring near-field beams 439 a, 439 b, 439 c and 439 d is reduced,resulting in robust and reliable power delivery in a wide area coveredby multiple wide beams (in this example four wide beams) to a single ormultiple slave devices in the near-field range.

Although, the present implementation shows that each respective antennaarray in each of RFIC modules 412 a, 412 b, 412 c and 412 d forms onebeam, it should be understood that RFIC modules 412 a, 412 b, 412 c and412 d may each divide its antenna array into smaller groups ofsub-arrays to form separate beams. For example, each of RFIC modules 412a, 412 b, 412 c and 412 d may form multiple beams. As the slave devicemoves even closer to master unit 408, master unit 408 may switch fromthe multi-beam mode to a customized beam pattern mode.

Referring to FIG. 4C, FIG. 4C illustrates an exemplary master unit in acustomized beam pattern mode according to one implementation of thepresent application. As illustrated in FIG. 4C, master unit 408 formsand steers customized beam pattern 439 toward the antennas of slavedevice 410. In the present implementation, master unit 408 in FIG. 4Cmay correspond to at least one of master units 108 a and 108 b in FIG.1, and master unit 208 in FIG. 2A. Slave device 410 in FIG. 4C maycorrespond to at least one of slave devices 110 a, 110 b, 110 c and 110d in FIG. 1, and slave device 310 in FIG. 3. As illustrated in FIG. 4C,master unit 408 includes RFIC modules 412 a, 412 b, 412 c and 412 d,each of which includes an antenna array of antennas 436.

As illustrated in FIG. 4C, in the customized beam pattern mode, fourantennas 436 from four different RFIC modules 412 a, 412 b, 412 c and412 d are selected to form sub-array 437. Antennas 436 in sub-array 437are utilized to form customized beam pattern 439 for transporting powerto slave device 410, while the rest of the antennas in RFIC modules 412a, 412 b, 412 c and 412 d are not utilized. The customized beam patternmode is advantageous in situations where slave device 410 is locatedwithin the near-field range of master unit 408's antennas 436.

In the customized beam pattern mode, a cost function (or optimizationcriteria) is defined where the target criteria is to maximize the amountof power collected by the antennas of slave device 410. The availableparameters are all the phase shifters and amplifiers driving antennas436 of master unit 408. The operating RF frequencies of the selectedgroup of antennas 436 may also be used as part of the optimizationprocess. In the present implementation, customized beam pattern 439illustrates an exemplary pattern created by the optimization processthat is different than the single-beam and multi-beam patterns in FIGS.4A and 4B, respectively. In the present example, customized beam pattern439 is formed by master unit 408 to deliver optimum power to individualantennas 490 and 492 of slave device 410.

Although a single slave device has been discussed to describe how masterunit 408 may dynamically reconfigure its RFIC modules 412 a, 412 b, 412c and 412 d to select from one of the three modes shown in FIGS. 4A, 4Band 4C, it should be understood that master unit 408 may alsodynamically reconfigure its RFIC modules 412 a, 412 b, 412 c and 412 dto select from one of the three modes based on the locations of multipleslave devices relative to master unit 408. For example, master unit 408may select the single beam mode by using all or substantially allantenna arrays in RFIC modules 412 a, 412 b, 412 c and 412 d to charge afar-field salve device. Master unit 408 may select the multi-beam modeby using each respective antenna array in each of RFIC modules 412 a,412 b, 412 c and 412 d to form a separate beam from each RFIC module tocharge multiple near-field slave devices. Master unit 408 may select thecustomized beam pattern mode by using a customized combination ofantennas in selected ones of RFIC modules 412 a, 412 b, 412 c and 412 dto charge a selected near-field slave device.

Referring to FIG. 5A, FIG. 5A illustrates an exemplary system forwireless charging according to one implementation of the presentapplication. As illustrated in FIG. 5A, master units 508 a and 508 b areutilized to deliver power to slave device 510. Master units 508 a and508 b may correspond to respective master units 108 a and 108 b inFIG. 1. Also, master units 508 a and 508 b may each correspond to masterunit 208 in FIG. 2A. In the present implementation, master units 508 aand 508 b may be coordinated through a feedback/control channel, such asWLAN/Bluetooth, to optimize the power delivery to slave device 510. Inone implementation, slave device 510 syncs and coordinates master units508 a and 508 b for optimum power delivery to slave device 510. Forexample, the relative phases of signals launched by master units 508 aand 508 b can he co-optimized for maximal power at the antennas of slavedevice 510. As illustrated in FIG. 5A, master units 508 a and 508 b areplugged into wall power outlets 598 a and 598 b, respectively. Inanother implementation, master units 508 a and 508 b can be built intofixtures or furniture (e.g., conference tables, walls, fitnessmachines), and have power cords connect them to a power source.

In one implementation master unit 508 a hands-off the charging of slavedevice 510 to master unit 508 b when slave device 510 moves further awayfrom master unit 508 a and moves towards master unit 508 b. In oneimplementation, master unit 508 a may use the location of slave device510 and use a feedback/control channel to hand-off the charging tomaster unit 508 b. In another implementation master unit 508 a may use anetwork database such as database 106 to hand-off the charging to masterunit 508 b. In another implementation slave device 510 can initiate orcoordinate the charging hand-off from master unit 508 a to master unit508 b. In yet another implementation a network server such as server 104can initiate or coordinate the charging hand-off from master unit 508 ato master unit 508 b.

Referring to FIG. 5B, FIG. 5B illustrates exemplary system for wirelesscharging according to one implementation of the present application. Asillustrated in FIG. 5B, master units 508 a and 508 b may correspond tomaster units 508 a and 508 b, respectively, in FIG. 5A. Master units 508a and 508 b may each be connected to a power outlet (not explicitlyshown in FIG. 5B), and coordinated with each other to charge slavedevice 510. As illustrated in FIG. 5B, master unit 508 a includes RFICmodules 512 a, 512 b, 512 c and 512 d, each of which includes an antennaarray. Master unit 508 b includes RFIC modules 512 o, 512 p, 512 q and512 r, each of which includes an antenna array. Master units 508 a and508 b each form and steer one or more beams toward slave device 510. Inone implementation, slave device 510 may use a low power wirelesscontrol link (e.g., a Bluetooth channel) to provide feedback to at leastone of master units 508 a and 508 b. In some implementations, masterunits 508 a and 508 b may coordinate with each other through a wirelesslink or a network. In the present implementation, master units 508 a and508 b are coordinated with each other to provide synchronized chargingfor slave device 510. For example, master units 508 a and 508 b arecoordinated such that the beams from master units 508 a and 508 b addconstructively at slave device 510. In some implementations, masterunits 508 a and 508 b may be configured to operate at two distinct RFfrequencies, for example, in cases where constructive addition at theantennas of slave device 510 may not be achievable reliably.

Referring to FIG. 6, FIG. 6 illustrates an exemplary slave deviceaccording to one implementation of the present application. Asillustrated in FIG. 6, slave device 610 includes antennas 640 a, 640 b,through 640 y, dual matching circuits 642 a and 642 b for antenna 640 a,dual matching circuits 642 c and 642 d for antenna 640 b, dual matchingcircuits 642 x and 642 y for antenna 640 y, dual phase shifters 644 aand 644 b for antenna 640 a, dual phase shifters 644 c and 644 d forantenna 640 b, dual phase shifters 644 x and 644 y for antenna 640 y,voltage multipliers 646 a, 646 b, through 646 y, rectifiers 648 a, 648b, through 648 y, configurable network of capacitors 652, and charger662. Slave device 610 may also include other components, such as WLAN/BTsub-system for control 654, memory 656, digital signal processor (DSP)for charging algorithms 658, and processor for programming,applications, and high-level algorithms 660.

As illustrated in FIG. 6, the capacitors collecting the harvested energyout of antennas 640 a, 640 b, through 640 y (using two polarizations andtwo feeds out of each antenna) form configurable network of capacitors652. Configurable network of capacitors 652 can be dynamicallyreconfigured to connect in series, in parallel, or in a combinationthereof, for optimal setting using the voltage level present at theoutput of antennas 640 a, 640 b, through 640 y (where the antennavoltage level is compared to the switch-on threshold of rectifiers 648a, 648 b, through 648 y). For example, when the received voltage levelis very weak, all capacitors in configurable network of capacitors 652are connected in series to generate an acceptable voltage level forcharging the battery. Alternatively, when the received voltage level isstrong, the capacities in configurable network of capacitors 652 areconnected in parallel for maximum charging current. For voltages inbetween, the capacities in configurable network of capacitors 652 mayutilize a combination of parallel and series configuration.

In one implementation, phase shifters 644 a, 644 b, 644 c, 644 d,through 644 x, and 644 y are optional for power combining acrossdifferent polarizations and antennas before delivering the combinedpower to the corresponding rectifiers, such as rectifiers 648 a through648 y. The reason is that in receiving power (as opposed to receivingdata signals) from antennas 640 a through 640 y, the relative signalphases may not be as critical since no data is being sought andpotential loss of data is not a concern. In a power receiving operation,it is the charging of configurable network of capacitors 652 that isimportant so that by proper voltage, current and power monitoring inslave device 610, the correct configuration of capacitors are charged toensure optimum voltage, current, and power delivered from configurablenetwork of capacitors 652 to slave device 610. Since the received powersignals by antennas 640 a through 640 y are being rectified byrectifiers 648 a through 648 y, the relative phases of the power signalsreceived by antennas 640 a through 640 y will not significantly affectthe output of rectifiers 648 a through 648 y delivered to configurablenetwork of capacitors 652. Thus, in this implementation, phase shifters644 a, 644 b, 644 c, 644 d, through 644 x, and 644 y are optional.

In some implementations, the configurations at the master unit aredetermined based on an optimization function for power delivery. Thepropagation effect between the transmission and reception can be modeledby an M×N complex matrix, where M is the number of antennas contained inthe master unit, and N is the number of antennas contained in the slavedevice. Each antenna feed at the master unit (transmission) and/or theslave device (reception) sides may include a programmable phase shifterfor altering the phase of the RF signals and a programmable amplifierfor altering the power of the RF signals. This response is not limitedto far-field and can be utilized even if in the near-field range.

The following is the procedure for optimization of power delivery to theslave device:

$\begin{matrix}{{\begin{bmatrix}r_{1} \\\vdots \\r_{N}\end{bmatrix} = {\begin{bmatrix}h_{11} & \ldots & h_{1M} \\\vdots & \ddots & \vdots \\h_{N\; 1} & \ldots & h_{NM}\end{bmatrix} \times \begin{bmatrix}{\exp \left( {j\; \phi_{1}} \right)} \\\vdots \\{\exp \left( {j\; \phi_{M}} \right)}\end{bmatrix} \times P}},{where}} & {{Equation}\mspace{14mu} (1)} \\{{H = \begin{bmatrix}h_{11} & \ldots & h_{1M} \\\vdots & \ddots & \vdots \\h_{N\; 1} & \ldots & h_{NM}\end{bmatrix}},} & {{Equation}\mspace{14mu} (2)}\end{matrix}$

is the multiple input and multiple output (MIMO) channel response matrixwith complex value for its elements. The master unit can utilize the M×Ncomplex matrix H to determine phase shift values for antennas used inany of the three modes described with reference to FIGS. 4A through 4 C.For example, the master unit may utilize H to determine the phase shiftvalues for the customized combination of antennas used in the customizedbeam pattern mode shown in FIG. 4C. P is the power being transmitted byeach of the antennas at the master unit. The phase shifters' vector canbe defined as:

$\begin{matrix}{{\Phi = \begin{bmatrix}{\exp \left( {j\; \phi_{1}} \right)} \\\vdots \\{\exp \left( {j\; \phi_{M}} \right)}\end{bmatrix}},} & {{Equation}\mspace{14mu} (3)}\end{matrix}$

where exp(jφ₁) is the effect of phase shifters incorporated at themaster unit when configurable phase value φ₁ is applied. These valuesacross all antennas at the master unit are optimized to lead to maximumpower delivery to the slave device. Finally, r₁ through r_(N) depict thereceived signals at the 1st through Nth antenna of the slave deviceunder charge. Several optimization procedures may be deployed dependingon the capabilities of the slave device.

With no loss of generality, the following are specific examples of powerdelivery optimization. In the present implementation, the master unitmay utilize a cost function for configuring its corresponding phaseshifters coupled to the antennas used in any of the three modesdescribed with reference to FIGS. 4A through 4C to optimize charging forone or more slave devices. It is noted that the power delivery and poweroptimization techniques discussed herein (that utilize various costfunctions) are particularly suitable for use in the customized beampattern mode for optimizing the charging of a selected near-field slavedevice discussed in relation to FIG. 4C.

As an example of the cost function, the combined power received by theslave device's antennas can be expressed as:

|r ₁|² + . . . +|r _(N)|² =P ²×Φ*×H*×H×Φ  Equation (4),

where Φ* is the complex conjugate and transpose of Φ. The vector (p isthen solved for maximizing the above cost function. One solution wouldbe the Eigen-vector associated with the maximum Eigen value. Dependingon the capacitor network and receiver implementation, other costfunctions may be utilized for configuring the transmitter phaseshifters. For example, a different cost function may be

|r₁+ . . . r_(N)|²   Equation (5)

In this case, the vector Φ is solved for maximizing this different costfunction. In some implementations, the following cost function may bedeployed:

|r₁|^(k)+ . . . +|r_(N)|^(k)   Equation (6),

for a k value other than 2. In some implementations, k=1, 1.5, or 2.5may be utilized for cost function definition depending on thecharacteristics of components used in the slave device. The choice ofcost function is driven or determined at least partly based on thestructure in which the capacitors in configurable network of capacitors652 in FIG. 6 are wired and interconnected.

In some implementations, power delivery techniques and architecture areapplicable to both line-of-sight (LOS) conditions, as well asnon-line-of-sight (NLOS) conditions. When a LOS path to a slave deviceis not available, the system may perform power delivery through a strongreflector in the environment. Under some implementations, the beampatterns creation would then point towards a strong reflector which inturn reflects the power towards the slave device. In someimplementations, the environment is modified with strong reflectors thatreflect most of the energy.

The power delivery techniques and architecture of this disclosure areapplicable to both near-field and far-field regions. While thepropagation model for near and far-field regions may be different, theimplementations are applicable and functional in both regions.

For example, the channel response matrix given by:

$\begin{matrix}{H = \begin{bmatrix}h_{11} & \ldots & h_{1M} \\\vdots & \ddots & \vdots \\h_{N\; 1} & \ldots & h_{NM}\end{bmatrix}} & {{Equation}\mspace{14mu} (2)}\end{matrix}$

above, would have a different characteristics and properties in thenear-field versus the far-field. However, the same solutions andframeworks can be applicable for both near- and far-field regions.

In some implementations, a master unit (charging device) may beservicing multiple slave devices concurrently or in a time-multiplexedmanner. In some implementations, the master unit may use different timeslots to deliver power to different slave devices, where in each timeslot a different beam pattern is utilized for best power deliveryperformance. In some implementations, the master unit may includemultiple arrays (distributed antenna arrays within the master unit),where different distributed antenna arrays are activated and configuredaccordingly to deliver power to each of the slave devices concurrentlyand in the same frequency channel. In such implementations, the beampatterns of each antenna array within the master unit is configured forbest power delivery performance towards the associated slave device.

Referring to FIG. 7, FIG. 7 illustrates a coexistence of multiplexedpower and data delivery in time domain according to one implementationof the present application. A system for wireless charging may utilizeand share the same frequency band that is used for communication betweenthe master unit and the slave devices in the vicinity, or even the samefrequency band that is used for data communication between the masterunit and the slave devices. FIG. 7 shows two time-domain multiplexingschemes for delivering both power (in the Power Time Slot) and data (inthe Data Time Slot) in the same frequency band. The two exemplaryschemes can be used in, for example, a WiFi wireless network. The “DataTime Slot” in FIG. 7 is reserved or scheduled for data delivery. Regulardata packets are deployed by nodes and devices for data communication(e.g., WLAN packets being exchanged between devices). In someimplementations, the access point or master unit may request and reservea time slot period. This is allowed under many wireless systems (e.g.,IEEE 802.11 MAC protocol). However, the time slot reserved under theIEEE 802.11 protocol is subsequently utilized for sending power deliverysignals or power bursts. That is due to the fact that those time slotswere previously negotiated and reserved by the master unit. Theadvantage is that since those time slots were previously negotiated andreserved by the master unit, other WLAN devices in the vicinity wouldavoid using the “Power Time Slots” of FIG. 7 for data packet deliveryand hence prevent losing those data packets due to interference by thepower bursts.

As shown in FIG. 7, two power time slot variations may be deployed, asnoted by scheme 1 and scheme 2. In scheme I, the master unit transmits apacket header and a packet payload in a data time slot, followed by apower burst in a power time slot for charging at least one slave device.In scheme 1, the entire packet length is utilized for power deliverywith no information embedded. In scheme 2, the master unit transmits apacket header and a packet payload in a data time slot, followed byanother packet header and a power burst in a power time slot forcharging at least one slave device. In scheme 2, an IEEE 802.11compliant (or any other standard utilized in the band of operation)packet header is pre-appended to the power delivery portion of the powerburst. In this implementation, some information bits can be transmittedto the slave device. Furthermore, the header can be decoded by otherWLAN devices in the vicinity. These WLAN devices would then decode thepacket header portion (as is typically done by the WLAN devices forlistening and monitoring channel usage) and estimate the length of thepacket. These devices would then know the length of the power burstperiod following the header, and avoid initiating or transmitting anydata in that period.

Referring to FIG. 8, FIG. 8 illustrates a coexistence of multiplexedpower and data delivery in frequency domain according to oneimplementation of the present application that can be utilized in, forexample, a WiFi wireless network. FIG. 8 illustrates implementationswhere coordination in the frequency domain is utilized for concurrentlytransporting data and power (to the same device or to differentdevices). In scheme 1, the master unit is configured to transmit a powerburst in a frequency band between two data packet frequency bands. Inscheme 1, the gap between the two standard frequency bands is utilizedfor transmitting a narrow bandwidth but high power burst for powerdelivery. The gap typically exists in many standard wireless systems(e.g., WLAN channels in 2.4 GHz and 5 GHz). This is feasible becausepower delivery can be achieved over a very narrow channel/frequency band(unlike data links that require higher bandwidth for throughput andcapacity). In scheme 1, the power level of the power burst is adjustedto avoid saturating the receivers of the slave devices that are decodingfrequency bands 1 and 2 (hence avoid corrupting their data packets).

In scheme 2 of FIG. 8, the master unit is configured to transmit a powerburst in a narrow frequency band within a data packet wide frequencyband. In scheme 2, the two signals, one for data and another for power,are effectively transmitted over the same frequency band and at the sametime. The protection for the data waveform is achieved by the verynarrowband nature of the power burst and the wideband nature of the datapacket. In this case, the data receiver on the slave device nulls thesmall portion of frequency corrupted by the power burst, for example, byusing a sharp frequency notching filter. Given the small ratio betweenthe narrow frequency band of the power burst and the wide frequency bandof the data packet, the impact on the quality of the decoded data can beminimal and manageable. In scheme 2, the master unit and the slavedevice (and other WLAN devices in the vicinity) coordinate and/ornegotiate the exact narrow frequency band of the power burst. Thisenables all the other devices that are receiving data packets in thesame wide frequency band to know in advance the frequency domainlocation of the power burst and filter/notch it out accordingly.

In another implementation, in scheme 2 of FIG. 8, the power burst may bealigned to fall onto the portion of the frequency band that is used asguard subcarriers, or direct-current, or embedded pilot subcarriers. Forexample, in many IEEE 802.11, OFDM, and PHY specifications, severalsubcarriers are not loaded with information data. Most notably, guardand DC subcarriers are provisioned for assisting the receiver and hencedo not carry information bits. In this implementation, the power burstis designed and generated to fall onto those subcarriers (henceminimizing the notch-filtering requirements at the data receivers).

In some implementations, the same frequency band may be utilized fordelivering both wireless power and wireless data between the master unitand the slave device. In this case, similar co-existence and schedulingmethods may be used by the master unit. For example, the master unitcould schedule and allocate non-overlapping transmit time slots forpower and data delivery. The duty cycle of these time slots may dependon several system parameters including, for example, targetcommunication throughput and level of battery charge at the slavedevice. In this case, the master unit informs the slave device about thescheduled time slots for power and data delivery for the next timeinterval. This allows the slave device to switch accordingly between thepower harvesting mode and the data reception mode at the expected timeslots. Similarly, non-overlapping frequency bands may be utilized by themaster unit to concurrently deliver power and data to the slave device.In this case, the power delivery can be achieved over a narrow frequencyband, whereas data delivery may require wider frequency band forefficient data communication. The master unit takes this tradeoff intoaccount when allocating and reserving frequency bands for power and datadelivery. For example, the master unit allocates very narrow frequencybands for power delivery, and allocates available wider frequency bandsfor data delivery. Additionally, the header portion (PHY or MAC) of datapackets during data delivery slots may be utilized to inform the slavedevice whether the following time slot is going to be utilized for powerdelivery or not. This allows the slave device to have sufficient timefor preparing and switching to the power harvesting mode.

FIGS. 7 and 8 depict two coexistence mechanisms: one coordinated in thetime domain and another in the frequency domain. In someimplementations, a combination of time domain and frequency domaincoexistence methods may be deployed. For example, a master unit (chargerunit) may use time scheduling to deliver power bursts in one frequencyband to two slave devices, while relying on using a different frequencyband to deliver power bursts to a third slave device.

From the above description it is manifest that various techniques can beused for implementing the concepts described in the present applicationwithout departing from the scope of those concepts. Moreover, while theconcepts have been described with specific reference to certainimplementations, a person of ordinary skill in the art would recognizethat changes can be made in form and detail without departing from thescope of those concepts. As such, the described implementations are tobe considered in all respects as illustrative and not restrictive. Itshould also be understood that the present application is not limited tothe particular implementations described above, but many rearrangements,modifications, and substitutions are possible without departing from thescope of the present disclosure.

1-20. (canceled)
 21. A master unit for wirelessly charging a pluralityof slave devices, said master unit comprising: a plurality of radiofrequency integrated circuit (RFIC) modules, each of said plurality ofRFIC modules being associated with a unique or a shared antenna array;said master unit having at least three charging modes, at least two ofsaid three charging modes comprising a multi-beam mode and a customizedbeam pattern mode; said master unit using each respective one of saidunique or said shared antenna array associated with each of saidplurality of RFIC modules to form separate beams from each of saidplurality of RFIC modules in said multi-beam mode; said master unitusing a customized combination of antennas in selected ones of saidplurality of RFIC modules to form a customized beam pattern in saidcustomized beam pattern mode.